In the past, a processing function has been known to be improved using a graphics processing unit (GPU), a field-programmable gate array (FPGA), or the like as an accelerator. An accelerator such as a GPU is expected to improve a performance of a specific application. Further, there are a wide variety of accelerators.
Generally, a processing performance is improved by mounting an accelerator used by an application to be executed in each host that executes an application. In this technique, since a central processing unit (CPU) of a host is connected with an accelerator in a one-to-one manner, when the CPU is broken, it is difficult to use the accelerator, and thus use efficiency of the accelerator is low. In recent years, a plurality of accelerators are mounted in an expansion I/O box of a PCI Express or the like, and a plurality of hosts use the accelerators via the expansion I/O box.
Patent Literature 1: Japanese National Publication of International Patent Application No. 2008-546072
Patent Literature 2: Japanese Laid-open Patent Publication No. 60-083168
Patent Literature 3: U.S. Patent No. 2004/0172494
However, the relation arts have a problem in that it is difficult to flexibly change an accelerator to be used by a host.
For example, when an expansion I/O box of a PCI Express is used, a relation between a slot position of the expansion I/O box and a host is statically fixed. In other words, a host is associated with a slot in a one-to-one manner.
For this reason, in order to cause a host A using an accelerator A of a slot A to use another accelerator, the accelerator A mounted in the slot A is first pulled out, and then a desired new accelerator is manually mounted in the slot A. Then, processing such as rebooting is executed on the host A, and so the new accelerator is recognized. Further, when a correspondence of the host A is changed to a slot B, the host A is first shut down, and then switching control of the expansion I/O box is changed from a management server. As described above, since a relation between the host and the slot of the expansion I/O box is statically fixed, it is difficult to flexibly change an accelerator on a host.